1. Technical Field
The present invention relates to the technical field of an illumination device which irradiates light to a reflection-type display panel and an electrooptic apparatus.
2. Related Art
As an existing display using a liquid crystal device, a transmission-type liquid crystal device including a back light as a light source has been primarily used. However, power consumption has been needed to be reduced in a liquid crystal device which is mainly used in a mobile electronic apparatus. The transmission-type liquid crystal device requiring a back light has had limitations on the less power consumption. Therefore, a reflection-type liquid crystal device is eagerly being developed.
In the reflection-type liquid crystal device, natural light or the like from outside is used as a light source. Therefore, power consumption can be largely reduced. However, clear display cannot be achieved in a dark place, on the other hand. Therefore, in recent years, a reflection-type liquid crystal device including a front light has been disclosed. JP-A-2000-267097 is an example of related art.
With the reflection-type liquid crystal device including the front light, it is sufficient that the front light is turned ON or OFF depending on brightness of places at which the reflection-type liquid crystal device is used. Therefore, the reduction in power consumption of a mobile electronic apparatus including such reflection-type liquid crystal device can be achieved. Therefore, the mobile electronic apparatus does not consume the battery more than necessary so that the mobile electronic apparatus can be driven for a long time.
However, when the reflection-type liquid crystal device including the front light is used, there arises a problem that display visibility is deteriorated as follows. That is, light incident from a viewing side, or, an observer side, namely, so-called outside light is reflected by a metal portion of an electrode of a light emitting portion, or, light output to the viewing side from the light emitting portion, namely, so-called inside light is reflected by the metal portion. With this, a so-called dot is generated at a position on the light emitting portion arising the problem that display visibility being deteriorated.